XArray: Correct xa_store_range

The explicit '64' should have been BITS_PER_LONG, but while looking at
this code I realised I meant to use __ffs(), not ilog2().

Signed-off-by: Matthew Wilcox <willy@infradead.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/lib/xarray.c b/lib/xarray.c
index 7946380cd6c9..bbacca576593 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -1565,8 +1565,9 @@ void *xa_store_range(struct xarray *xa, unsigned long first,
         do {
                 xas_lock(&xas);
                 if (entry) {
-                        unsigned int order = (last == ~0UL) ? 64 :
-                                                ilog2(last + 1);
+                        unsigned int order = BITS_PER_LONG;
+                        if (last + 1)
+                                order = __ffs(last + 1);
                         xas_set_order(&xas, last, order);
                         xas_create(&xas);
                         if (xas_error(&xas))